1# Connecting to a ServiceAbility 2 3 4If a ServiceAbility wants to interact with a PageAbility or a ServiceAbility in another application, you must first create a connection by calling [connectAbility()](../reference/apis-ability-kit/js-apis-ability-featureAbility.md#featureabilityconnectability7). This method is defined in the [featureAbility](../reference/apis-ability-kit/js-apis-ability-featureAbility.md) class for the PageAbility and in the [particleAbility](../reference/apis-ability-kit/js-apis-ability-particleAbility.md) class for the ServiceAbility. For details about the connection rules, see [Component Startup Rules](component-startup-rules-fa.md). When using **connectAbility()** to process the callback, pass in the instances of [Want](../reference/apis-ability-kit/js-apis-app-ability-want.md) and [IAbilityConnection](../reference/apis-ability-kit/js-apis-inner-ability-connectOptions.md) of the target ServiceAbility. [IAbilityConnection](../reference/apis-ability-kit/js-apis-inner-ability-connectOptions.md) provides the following callbacks that you should implement. 5 6 7**Table 1** IAbilityConnection APIs 8 9| API| Description| 10| -------- | -------- | 11| onConnect() | Callback invoked when the ServiceAbility is connected.| 12| onDisconnect() | Callback invoked when the ServiceAbility is disconnected.| 13| onFailed() | Callback invoked when the connection to the ServiceAbility fails.| 14 15 16The following sample code enables the PageAbility to create connection callback instances and connect to the local ServiceAbility: 17 18```ts 19import featureAbility from '@ohos.ability.featureAbility'; 20import common from '@ohos.app.ability.common'; 21import Want from '@ohos.app.ability.Want'; 22import promptAction from '@ohos.promptAction'; 23import rpc from '@ohos.rpc'; 24import hilog from '@ohos.hilog'; 25``` 26```ts 27const TAG: string = 'PageServiceAbility'; 28const domain: number = 0xFF00; 29 30@Entry 31@Component 32struct PageServiceAbility { 33 //... 34 build() { 35 Column() { 36 //... 37 List({ initialIndex: 0 }) { 38 ListItem() { 39 Row() { 40 //... 41 } 42 .onClick(() => { 43 let option: common.ConnectOptions = { 44 onConnect: (element, proxy) => { 45 hilog.info(domain, TAG, `onConnectLocalService onConnectDone element:` + JSON.stringify(element)); 46 if (proxy === null) { 47 promptAction.showToast({ 48 message: 'connect_service_failed_toast' 49 }); 50 return; 51 } 52 let data = rpc.MessageParcel.create(); 53 let reply = rpc.MessageParcel.create(); 54 let option = new rpc.MessageOption(); 55 data.writeInterfaceToken('connect.test.token'); 56 proxy.sendRequest(0, data, reply, option); 57 promptAction.showToast({ 58 message: 'connect_service_success_toast' 59 }); 60 }, 61 onDisconnect: (element) => { 62 hilog.info(domain, TAG, `onConnectLocalService onDisconnectDone element:${element}`); 63 promptAction.showToast({ 64 message: 'disconnect_service_success_toast' 65 }); 66 }, 67 onFailed: (code) => { 68 hilog.info(domain, TAG, `onConnectLocalService onFailed errCode:${code}`); 69 promptAction.showToast({ 70 message: 'connect_service_failed_toast' 71 }); 72 } 73 }; 74 75 let request: Want = { 76 bundleName: 'com.samples.famodelabilitydevelop', 77 abilityName: 'com.samples.famodelabilitydevelop.ServiceAbility', 78 }; 79 let connId = featureAbility.connectAbility(request, option); 80 hilog.info(domain, TAG, `onConnectLocalService onFailed errCode:${connId}`); 81 }) 82 } 83 //... 84 } 85 //... 86 } 87 //... 88 } 89} 90``` 91 92 93When the ServiceAbility is connected, the [onConnect()](../reference/apis-ability-kit/js-apis-inner-ability-connectOptions.md#onconnect) callback is invoked and returns an [IRemoteObject](../reference/apis-ipc-kit/js-apis-rpc.md#iremoteobject) defining the proxy used for communicating with the ServiceAbility. The system provides a default implementation of **IRemoteObject**. You can extend [rpc.RemoteObject](../reference/apis-ipc-kit/js-apis-rpc.md#remoteobject) to implement your own class of **IRemoteObject**. 94 95 96The following sample code shows how the ServiceAbility returns itself to the caller: 97 98```ts 99import type Want from '@ohos.app.ability.Want'; 100import rpc from '@ohos.rpc'; 101import hilog from '@ohos.hilog'; 102 103const TAG: string = '[Sample_FAModelAbilityDevelop]'; 104const domain: number = 0xFF00; 105 106class FirstServiceAbilityStub extends rpc.RemoteObject { 107 constructor(des: Object) { 108 if (typeof des === 'string') { 109 super(des); 110 } else { 111 return; 112 } 113 } 114 115 onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean { 116 hilog.info(domain, TAG, 'ServiceAbility onRemoteRequest called'); 117 if (code === 1) { 118 let string = data.readString(); 119 hilog.info(domain, TAG, `ServiceAbility string=${string}`); 120 let result = Array.from(string).sort().join(''); 121 hilog.info(domain, TAG, `ServiceAbility result=${result}`); 122 reply.writeString(result); 123 } else { 124 hilog.info(domain, TAG, 'ServiceAbility unknown request code'); 125 } 126 return true; 127 } 128} 129//... 130``` 131